Papers by Poppe L de Boer
Annals of the New York Academy of Sciences, 1996
… Assembly 2009, held …, 2009
The commonly twice-a-day flooding and drainage largely defines the character and composition of s... more The commonly twice-a-day flooding and drainage largely defines the character and composition of sediments of the intertidal zone. Sediments are supplied through nearby delta distributaries. by the erosion of headlands, from the adjacent sea floor, and, from greater distances. in suspension. In situ production of sediment by biological activity (carbonate, organic matter) may be an additional (temperate climates) to dominant (dry tropical and subtropical climates) source of sediment. Depending on the available sediment and the (varying) energy levels, intertidal areas consist of sandy, silty, and muddy sediments, and mixtures of these. Grain size commonly decreases from high-energy toward low-energy, more sheltered parts. Vegetation, which can be abundant in the more quiet parts of the intertidal zone, may not be directly apparent in lower-lying. higher-energy zones, but it is there, normally represented by algae, as is testified by the common abundance of burrowing and grazing organisms which feed on them or their remains. Relatively quiet parts of intertidal systems may be occupied by organic buildups. such as oyster and mussel beds. Sedimentary structures (Table 7.1) reflect the various energy levels. All tidal systems show a neap-spring cycle with a regular fluctuation of highwater and low-water levels in about 14 days. As seen in Chapter I, the most frequently occurring tidal system is the semidiurnal one, with two tidal cycles in slightly more than a day (24 h 40 min). A limited part of the coasts on Earth (about 10%. Lisitzin 1974) is characterized by diurnal tides, with only one tidal cycle a day. Mixed tidal systems experience an alternation of semidiurnal and diurnal characteristics during the neap-spring cycle. Semidiurnal systems generally have a larger difference between low water and high water (more than 10 m in extreme cases, e.g., the Bay of Fundy) than diurnal and mixed systems. Such a difference in tidal amplitude defines differences in current velocities in diurnal and semidiurnal systems in two ways. First. the generally greater tidal amplitude in semi diurnal systems makes their tidal-current strength greater than in diurnal ones. Second, in semidiurnal tidal systems six hours separate high water from low water and vice versa. while this period is doubled in diurnal systems. Thus, in cases of the same tidal amplitude, maximum current velocity in the semidiurnal system will be twice that of diurnal 345 346 Intertidal Deposits: River Mouths, Tidal Flats, and Coastal Lagoons TABLE 7.1 Selection of Features Typical for Intertidal Deposits Unidirectional Lower phase plane bed Small-scale ripples-straight and sinuous: immature; Iinguoid: mature; Baas et aI., 1993 Erosive ripple forms-Reineck and Singh, 1973, their Figure 7.8 Back-flow ripples-small-scale ripples formed in troughs of large-scale ripples through backflow; Boersma et aI., 1968 Megaripples, dunes-straight-crested, undulatory/sinuous, lunate Tidal bundle sequences-series of, ideally, about 28 megaripple foresets of increasing and decreasing thickness, formed due to the increasing and decreasing transport capacity of tidal currents during a neap-spring-neap-neap period; in intertidal environments only one (high-slack water) mud drape can be deposited Upper phase plane bed-current lineation Antidunes-extremely low preservation potential Graded beds-deposited during storms Bidirectional Ebb caps on megaripples; Boersma and Terwindt, 1981 Flaser-Iinzen bedding; Reineck and Singh, 1973 Wave ripples Combined ripples produced by the combined action of waves and currents with different directions Interference ripples; combination of wave and/or current ripples with different direction; Reineck and Singh, 1973 Adhesion ripples; accretion of generally pre-existing ripple forms due to aeolian transport during low water; van Straaten, 1953 Runoff Structures Microdeltas in channels along shoals with runoff through small gullies Rill marks; Reineck and Singh, 1973 Shell lags; scour marks, Figure 7.10 Figure 7.11; see also Dionne, 1988 Load cast Cavernous sand, Emery, 1945 Convolute lamination; de Boer, 1979 Mud volcanoes Mud cracks produced by desiccation Erosional Structures Tool Marks Deformation Structures Slumps and Faults Formed due to slope instability, e.g., along the margins of channels Bioturbation U burrows
Paleomagnetism and astronomically induced cyclicity
Distally steepened carbonate ramps are gently inclined sea floors with a marked break in slope im... more Distally steepened carbonate ramps are gently inclined sea floors with a marked break in slope immediately basinwards of the carbonate factory (Fig. 1). Progradation occurs in particular through deposition on the ramp slope giving rise to the formation of seismic-scale clinoforms up to tens of metres in height. In temperate waters such as the present-day Mediterranean Sea, non-tropical biological associations generate sandand gravel-sized material. Such skeletal debris remains loose on the sea bed in the absence of the early cementation and coral build-ups that characterise tropical settings. Consequently, under the influence of shallowmarine unidirectional currents, subaqueous dunes ranging from smallto large-scale (sensu Ashley, 1990) may develop on carbonate ramps (e.g. Fornos & Ahr, 2006). Their preservation is most likely in the ramp slope zone. The sedimentary record contains numerous examples of biocalcarenite and -calcirudite bodies that formed by the lateral stacking of sub...
Paleogeography, Paleoclimate, and Source Rocks, 1995
The distribution of organic carbon in marine sediments is commonly characterized by cyclicity at ... more The distribution of organic carbon in marine sediments is commonly characterized by cyclicity at different time scales. A detailed analysis of such cyclicity in three case studies of Liassic and Kimmeridgian age in England and of Cenomanian age in the northwestern Atlantic Ocean shows that specific processes playing at different time scales control the storage of organic matter. Two scales are distinguished: (1) large-scale trends (>3 m.y., 2nd- and 3rd-order cycles) are caused by plate tectonics affecting paleogeography and topography, long-term eustatic sea level, and climatic changes ("ice-house" and "green-house"); they define the storage of organic matter worldwide by influencing productivity and ventilation of deep water; and (2) small-scale trends (<3 m.y., 4th- and 5th-order cycles) are caused by orbitally induced high-frequency glacio-eustatic and other oceanographic and/or climatic changes. If general conditions are favorable, the impact of these changes is a high-frequency signal of oxygenation/dilution cycles, whose particular expression strongly depends on the local sedimentary environment. A consequence of the orbitally induced climatic/oceanographic control of high-frequency sedimentary cycles is that it has a regional (to worldwide)
Late Cenozoic sedimentation in the North Sea Basin was dominated by a large clastic depositional ... more Late Cenozoic sedimentation in the North Sea Basin was dominated by a large clastic depositional delta system that progressively built out into a shallow sea. Sediments were mainly delivered by rivers draining the Fennoscandian Shield and the Baltic Platform in the northeast and east with a drainage area of 1.100.000 km2. This huge river system was active until Late Pliocene,
Journal of the Geological Society, 2014
M arine evaporites such as the Zechstein (Permian, NW Europe) consist of thinning-upward sulphate... more M arine evaporites such as the Zechstein (Permian, NW Europe) consist of thinning-upward sulphate-halite-potash cycles whose origin is poorly understood. An intra-basinal mechanism presented here explains well their mineral composition and cycle development. It involves the progressive obstruction of ocean connections by sulphate-platform progradation, causing a chain reaction of outflow reduction and subsequent accelerated sulphate precipitation. Numerical modelling shows this to be a self-accelerating process that ultimately triggers halite and potash precipitation. Isostatic compensation of the salt load explains the formation of accommodation space for subsequent cycles, each about half the thickness of the previous cycle.
Primary production of organic matter in stagnant-basin settings is low. Nevertheless, black shale... more Primary production of organic matter in stagnant-basin settings is low. Nevertheless, black shales are formed and preserved because of poor or no oxygen refreshment in deep water. In high-productivity, upwelling settings, on the other hand, primary productivity of org C is high, and black shales are formed and preserved because the supply of org C is too great, relative to
Morphology of crater lake deltas indicates formative time scale, sediment flux and water flux. Ou... more Morphology of crater lake deltas indicates formative time scale, sediment flux and water flux. Our new morphological model predicts quantitative morphology which we compare to DTM data. Five studied deltas formed in less than ten years.
Tectonophysics, 1996
An integrated approach combining the available geological-geophysical information was employed to... more An integrated approach combining the available geological-geophysical information was employed to construct a series of paleogeographic maps of the northwestern part of the Dnieper Donets Basin (DDB) during the Late Visean-Serpukhovian (Early Carboniferous). The major source of information consists of well-log data. The basin fill shows a pattern of stacked transgressive-regressive units of different order. Correlations on the scale of the basin are based on biostratigraphy, seismics, cyclostratigraphic subdivisions and correlations of the successions throughout the basin. The cyclicity has a multifold character. 'Short' shallowing-upward transgressive-regressive (T-R) cycles, characterized by the presence of hydrocarbons ('productive horizons'), cover a time span of the order of 500 ka. 'Long' cycles include 4 to 6 short T-R cycles. They seem to be correlatable to Western Europe and probably to North America. The long cycles form part of higher-order stacking patterns indicative of still longer cycles. Considering the variable thickness of the cycles throughout the basin, tectonics must have influenced the character of the series in addition to (glacio-)eustatic sea-level fluctuations. The paleogeographical development of the basin shows axial deposition during the late Visean, likely related to late-stage rifting-related subsidence of a central graben, followed by basin-wide subsidence related to thermal subsidence during the Serpukhovian.
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1987
"Be measurements of samples from a (hemi)pelagic sequence of Middle Miocene to Lower Pliocene age... more "Be measurements of samples from a (hemi)pelagic sequence of Middle Miocene to Lower Pliocene age (Java, Indonesia) allow estimating the rate of sedimentation and the tirnespan during which deposition occurred. Large variations of 'OBe values between adjacent samples can be satisfactorily ascribed to short term variations of the rate of sedimentation, with in addition downslope mass transport of sedimentary units that had previously been deposited higher on the submarine slope.
Geophysical Research Letters, 1997
The results are presented of a detailed study of a short (250 kyr) interval from a cyclically bed... more The results are presented of a detailed study of a short (250 kyr) interval from a cyclically bedded continental sequence that is composed of alternating reddish silts and whitish limestones (Armantes section, Central Spain). The lithology as well as the carbonate and gamma-ray records indicate that five smallscale cycles are developed in one large-scale cycle, implying that the small-scale cyclicity is related to precession and thus caused by climate forcing. Rock magnetic experiments show that the NRM is carried by hematite and magnetite/maghemite and that the relative contribution of hematite is related to lithology. The positions of the reversal boundaries can reliably be determined, even though reversals of the magnetite and hematite components appear to be recorded at slightly different levels. We conclude that the well-developed cyclicity and the good paleomagnetic properties of the sediments will enable the construction of an astronomical polarity time scale (APTS) for the continental realm.
Mededelingen van de …, 1988
Kolfschoten, T. van, & P. L. de Boer. The Zuurland-2 borehole: some remarks on the results of the... more Kolfschoten, T. van, & P. L. de Boer. The Zuurland-2 borehole: some remarks on the results of the geological and palaeontological investigations.-Meded. Werkgr. Tert. Kwart. Geol., 25(1): 99-106, 2 tabs. Leiden, March 1988. This paper compares and evaluates the preliminary results obtained by the various disciplines on the stratigraphical and palaeontological interpretation of the Zuurland-2 borehole section (0 to-64 m) at Brielle, The Netherlands, as published in the present issue of this periodical.
Introduction: Deltas, fans and channels on Mars clearly indicate surface water in the past. These... more Introduction: Deltas, fans and channels on Mars clearly indicate surface water in the past. These landforms contain valuable information about the duration and magnitude of surface-water flow, with obvious implications for potential life on Mars. Martian fan-shaped deposits such as deltas and alluvial fans show architectural elements similar to those of terrestrial analogs, e.g. lobes, terraces, and incised delta fronts. Pilot experiments demonstrate that delta morphology is related to flow discharge and duration, sediment properties, and crater size [1]. However, the important relationships between surface morphology and climate remain unquantified and it is difficult to unambiguously relate the architecture of sediment bodies to certain boundary conditions. The objectives of this study are to qualify and quantify the morphological elements of Martian fan-shaped deposits with the use of the unique remote sensing data by Mars Express-HRSC. Discussion: The population of fan-shaped deposits on Mars varies greatly in terms of size, shape and morphology. In order to understand the processes involved in their formation, and hence the climate conditions under which they were formed, one must first establish whether it is possible to distinguish between different types of these deposits. Some authors have done this based on the setting in which the deposits were formed (e.g. in ponding water, in impact crater basins, within 30° of the equator, etc.). We attempt to distinguish different types by analysing morphometric properties and key architectural elements. Key Architectural Elements: Terrestrial alluvial systems are classified on basis of characteristic features such as size, gradient and shape, as well as external factors such as the up-and downstream conditions that allude to their depositional history [2]. Processes that range from episodic land sliding and debris flows to continuous stream flow result in various types of alluvial and fluvial fans, so providing insight into the type of climate that controlled their deposition [3]. We quantify key architectural elements of the Martian deposits using images and Digital
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Papers by Poppe L de Boer
De belangrijkste voorwaarde is dat de bodemdaling door de gaswinning samen met de zee-spiegelstijging binnen de toegestane gebruiksruimte blijft.1 De andere voorwaarde is dat de (dynamische) natuur in en rondom de Waddenzee2 niet wordt aangetast door bodemdaling als gevolg van de gaswinning. Mocht dit wel het geval zijn dan wordt de gaswinning beperkt of gestopt. Dit is het zogenaamde ‘Hand aan de kraan’-principe. Om te bepalen of aan deze voorwaarden wordt voldaan, is in het Rijksprojectbesluit en de Natuurbeschermingswetver-gunningen (verder de Nb-wetvergunningen) bepaald dat de bodemdaling en de natuurwaar-den moeten worden gemonitord door de NAM. De NAM rapporteert jaarlijks over de monitoring aan de minister van Economische Zaken (EZ).
zeespiegelstijging niet meer mag zijn dan 5 of 6 mm/jaar.1 De andere randvoorwaarde is dat de (dynamische) natuur in en rondom de Waddenzee2 niet wordt aangetast door bodemdaling als gevolg van de gaswinning. Mocht dit wel het geval zijn dan wordt de gaswinning beperkt of gestopt. Dit is het zogenaamde “hand aan de kraan” principe. Om te bepalen of aan deze randvoorwaarden wordt voldaan, is in het Rijksprojectbesluit en de Natuurbeschermingswetvergunningen (verder de Nb-wetvergunningen) bepaald dat de bodemdaling en de natuurwaarden moeten worden gemonitord door de NAM. De NAM rapporteert jaarlijks over de monitoring aan de minister van Economische Zaken (EZ).